It is well known in the railroad industry that there is a significant need to assure that the gage of the rails meet certain minimum and maximum requirements to assure optimum travel along the rails while preventing derailment. Several U.S. patents have issued for devices relating to this problem.
U.S. Pat. No. 325,706 shows a gage and level indicating device for railroad tracks wherein a mechanical three point rail contact apparatus is sprung against the inside of the rail to indicate gage variations on a scale. U.S. Pat. No. 3,050,015 shows track lining equiptment comprising a track alignment car having wheels on one side which cannot move outward and wheels on the other side which can move outward. U.S. Pat. No. 3,750,299 shows a laser beam reference track apparatus. U.S. Pat. No. 3,869,805 shows a track level indicator comprising a pendulum potentiometer which indicates differences in elevation between rails. U.S. Pat. No. 3,990,154 shows apparatus for measuring the distance between rails comprising a frame having rollers moveably mounted to one rail and a rail sensing roller which presses against the opposite rail to measure a distance between the rails. U.S. Pat. No. 4,027,397 shows a mobile track surveying apparatus comprising two spaced apart bogies, grade measurement means, a theodolite, and gage measurement means further comprising a pointer to indicate track gage on a scale which is located on an axle. While several of these inventions have provided means for measuring the distance between rails, there has remained a need for a simple, inexpensive, track gage measurement device adapted for mounting on one of several railroad vehicles. It is for this reason that the present railroad track gage was invented.